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Accurate measurement of the cosmogenic muon-induced neutron yield is crucial for constraining a significant background in a wide range of low-energy physics searches. Although previous underground experiments have measured this yield across various cosmogenic muon energies, SNO+ is uniquely positioned due to its exposure to one of the highest average cosmogenic muon energies at \\(364\\,\\text{GeV}\\). Using ultra-pure water, we have determined a neutron yield of \\(Y_{n}=(3.38^{+0.23}_{-0.30})\\times10^{-4}\\,\\text{cm}^{2}\\text{g}^{-1}\\mu^{-1}\\) at SNO+. Comparison with simulations demonstrates clear agreement with the FLUKA neutron production model, highlighting discrepancies with the widely used GEANT4 model. Furthermore, this measurement reveals a lower cosmogenic neutron yield than that observed by the SNO experiment, which used heavy water under identical muon flux conditions. This result provides new evidence that nuclear structure and target material composition significantly influence neutron production by cosmogenic muons, offering fresh insight with important implications for the design and background modelling of future underground experiments.

The SNO+ collaboration reports its second spectral analysis of reactor antineutrino oscillation using 286 tonne-years of new data. The measured energies of reactor antineutrino candidates were fitted to obtain the second-most precise determination of the neutrino mass-squared difference \\(\\Delta m^2_{21}\\) = (\\(7.96^{+0.48}_{-0.42}\\)) \\(\\times\\) 10\\(^{-5}\\) eV\\(^2\\). Constraining \\(\\Delta m^2_{21}\\) and \\(\\sin^2\\theta_{12}\\) with measurements from long-baseline reactor antineutrino and solar neutrino experiments yields \\(\\Delta m^2_{21}\\) = (\\(7.58^{+0.18}_{-0.17}\\)) \\(\\times\\) 10\\(^{-5}\\) eV\\(^2\\) and \\(\\sin^2\\theta_{12} = 0.308 \\pm 0.013\\). This fit also yields a first measurement of the flux of geoneutrinos in the Western Hemisphere, with \\(73^{+47}_{-43}\\) TNU at SNO+.

The SNO+ collaboration reports its first spectral analysis of long-baseline reactor antineutrino oscillation using 114 tonne-years of data. Fitting the neutrino oscillation probability to the observed energy spectrum yields constraints on the neutrino mass-squared difference \\( m^2_21\\). In the ranges allowed by previous measurements, the best-fit \\( m^2_21\\) is (8.85\\(^+1.10_-1.33\\)) \\(\\) 10\\(^-5\\) eV\\(^2\\). This measurement is continuing in the next phases of SNO+ and is expected to surpass the present global precision on \\( m^2_21\\) with about three years of data.

The direction of individual \\(^8\\)B solar neutrinos has been reconstructed using the SNO+ liquid scintillator detector. Prompt, directional Cherenkov light was separated from the slower, isotropic scintillation light using time information, and a maximum likelihood method was used to reconstruct the direction of individual scattered electrons. A clear directional signal was observed, correlated with the solar angle. The observation was aided by a period of low primary fluor concentration that resulted in a slower scintillator decay time. This is the first time that event-by-event direction reconstruction in high light-yield liquid scintillator has been demonstrated in a large-scale detector.

The SNO+ Collaboration reports the first evidence of reactor antineutrinos in a Cherenkov detector. The nearest nuclear reactors are located 240~km away in Ontario, Canada. This analysis uses events with energies lower than in any previous analysis with a large water Cherenkov detector. Two analytical methods are used to distinguish reactor antineutrinos from background events in 190 days of data and yield consistent evidence for antineutrinos with a combined significance of 3.5\\(\\sigma\\).

This study had two objectives. The first was to evaluate the possibility that, in a previous study, a soup preload augmented the reduction of food intake in a test meal induced by an exogenous infusion of cholecystokinin (CCK) because the soup also endogenously released CCK. The second was to compare CCK release by soup between men and women to determine whether the increased satiating effectiveness of soup in women as opposed to men could have been partly attributable to differences in CCK release. By using a bioassay that measures all of its known isoforms, we determined plasma CCK levels at baseline and at several times postprandially in eight healthy, non-obese men and women (four of each sex). Each subject ingested 800 g of tomato soup, which was followed 30 min later by 300 g of a yogurt shake. Appetitive ratings were also collected and related to CCK levels. Ingestion of tomato soup significantly increased plasma CCK levels by 3.81 pmol/L (± 1.21 standard error, P = 0.016) over baseline within 30 min in all subjects combined. When CCK concentrations at 5 min after soup and 5 min after yogurt were averaged, the women’s mean averaged concentration was 5.58 pmol/L (± 1.994, t = 2.80, P = 0.0073) higher than the men’s. The elevated levels persisted but did not rise further upon consumption of the yogurt shake. Hunger ratings declined and fullness ratings increased after eating, although patterns of ratings did not match exactly patterns of CCK release. A large quantity of tomato soup stimulates significant CCK release; therefore, some of the satiating effects of soup preloads could have been mediated by an elevation in endogenous CCK.

This paper reports results from a search for single and multi-nucleon disappearance from the \\(^{16}\\)O nucleus in water within the \\snoplus{} detector using all of the available data. These so-called \"invisible\" decays do not directly deposit energy within the detector but are instead detected through their subsequent nuclear de-excitation and gamma-ray emission. New limits are given for the partial lifetimes: \\(\\tau(n\\rightarrow inv) > 9.0\\times10^{29}\\) years, \\(\\tau(p\\rightarrow inv) > 9.6\\times10^{29}\\) years, \\(\\tau(nn\\rightarrow inv) > 1.5\\times10^{28}\\) years, \\(\\tau(np\\rightarrow inv) > 6.0\\times10^{28}\\) years, and \\(\\tau(pp\\rightarrow inv) > 1.1\\times10^{29}\\) years at 90\\% Bayesian credibility level (with a prior uniform in rate). All but the (\\(nn\\rightarrow inv\\)) results improve on existing limits by a factor of about 3.

SNO+ is a large-scale liquid scintillator experiment with the primary goal of searching for neutrinoless double beta decay, and is located approximately 2 km underground in SNOLAB, Sudbury, Canada. The detector acquired data for two years as a pure water Cherenkov detector, starting in May 2017. During this period, the optical properties of the detector were measured in situ using a deployed light diffusing sphere, with the goal of improving the detector model and the energy response systematic uncertainties. The measured parameters included the water attenuation coefficients, effective attenuation coefficients for the acrylic vessel, and the angular response of the photomultiplier tubes and their surrounding light concentrators, all across different wavelengths. The calibrated detector model was validated using a deployed tagged gamma source, which showed a 0.6% variation in energy scale across the primary target volume.

The SNO+ experiment is located 2 km underground at SNOLAB in Sudbury, Canada. A low background search for neutrinoless double beta (\\(0\\)) decay will be conducted using 780 tonnes of liquid scintillator loaded with 3.9 tonnes of natural tellurium, corresponding to 1.3 tonnes of \\(^130\\)Te. This paper provides a general overview of the SNO+ experiment, including detector design, construction of process plants, commissioning efforts, electronics upgrades, data acquisition systems, and calibration techniques. The SNO+ collaboration is reusing the acrylic vessel, PMT array, and electronics of the SNO detector, having made a number of experimental upgrades and essential adaptations for use with the liquid scintillator. With low backgrounds and a low energy threshold, the SNO+ collaboration will also pursue a rich physics program beyond the search for \\(0\\) decay, including studies of geo- and reactor antineutrinos, supernova and solar neutrinos, and exotic physics such as the search for invisible nucleon decay. The SNO+ approach to the search for \\(0\\) decay is scalable: a future phase with high \\(^130\\)Te-loading is envisioned to probe an effective Majorana mass in the inverted mass ordering region.